1. Field of The Invention
The present invention relates to an electrically-connecting body for electrically connecting electronic devices such as an integrated circuit and a printed-circuit board provided with a surface mount spherical terminal or a flat surface type terminal used for various equipments together and to a manufacturing method thereof. In particular, the present invention relates to a thin (film-shaped) electrically-connecting body used for a high frequency test or the mounting of an electronic device and to a manufacturing method thereof.
2. Description of Related Art
In order to connect two electronic devices together, that is, in order to electrically connect a plurality of terminals disposed on the two electronic devices together, there is used an electrically-connecting body provided with a plurality of conductive connection elements. In the case of connecting two electronic devices together by the use of an electrically-connecting body, the connection elements with which the electrically-connecting body is provided have to be held to have a predetermined interval (pitch) by an insulator lest the terminals disposed on the area alley of each of the electronic devices should mutually cause short circuit.
As methods of forming an insulator in an electrically-connecting body and methods of fixing a connection element, there have conventionally been known a method where an insulator (carrier) provided with holes for housing the desired number of connection elements is manufactured by injection forming by the use of plastic having an insulation property to insert the connection elements in the holes (see Japanese Patent No. 3753615 and Japanese Patent No. 3860561), a method where holes are arranged in a plastic sheet having an insulation property with a puncher or the like by the use of a die to bond the plastic sheet to the connection elements by means of an adhesive such as an adhesive sheet (see Japanese Patent No. 3847227 and Japanese Patent No. 3703748), and a method where silicon rubber is stuck on glass fiber fabric or the like having no conductivity by overmolding or lamination, and then the connection elements are inserted with a special tool for exclusive use, or the connection elements are inserted in the holes which are made with a die such as a punch, a blade, a laser, or the like, followed by connecting the connection elements with fibers of the fabric (see Japanese Patent No. 4102196).
In the method disclosed in the Japanese Patent No. 3753615 and Japanese Patent No. 3860561, in the case of manufacturing an insulator (carrier) of an electrically-connecting body responding to electronic devices where miniaturization of the terminal and narrowing of the pitch proceed, a mixture of about 60% of glass fibers with a resin such as PPS or LCP is generally used as a material for forming. However, a die required for injection forming of the material has to have a hot runner structure to have small-sized parts, and the manufacturing employs a material having excellent high temperature strength. Therefore, the initial costs are high. In addition, in this method, an injection forming machine capable of thin high-speed filling is used, and it is necessary to keep the temperature of the die relatively high in the process of injection forming. Therefore, the running cost is high. Further, the initial cost for, for example, the tool for exclusive use used in the step of inserting the connection elements into the holes for the connection elements provided in the carrier is not low. Furthermore, in a test socket which is required to increase the speed, it is generally hoped that the entire length of the connection element is as short as possible. However, in order to manufacture a formed article having high density (narrow pitch) and small height (thin type) by injection molding, high techniques and a more expensive die are required which raises the costs more.
On the other hand, since the method disclosed in the Japanese Patent No. 3847227 and Japanese Patent No. 3703748 employs a sheet for the insulator, the method is easier than the method disclosed in the Japanese Patent No. 3753615 and Japanese Patent No. 3860561 regarding the manufacturing of an article having small height. However, hole-making is necessary for two kinds of materials for the sheet functioning as the insulator and the adhesive (adhesive sheet or the like). In particular, for the adhesive in this case, a thermosetting resin of an epoxy type, an imide type, or the like is often used as the adhesive material. Since holes are made to such a material by holding the material, which is relatively soft in a half-hardened state, between cover films, the shape of the hole is easily destroyed. In addition, it has a cost problem in that the life span of the die used for the hole-making becomes short. In addition, in the case of making holes in the sheet with a narrow pitch in order to respond to electronic devices where miniaturization of the terminal and narrowing of the pitch proceed, it is difficult to make holes by the use of a die. That is, in the case of making holes in a sheet with a die, the narrower the width of a sheet portion remaining between the holes to be made (remaining portion width) is, the more difficult the hole-making is. It is difficult to respond to a narrow pitch with the remaining portion width of smaller than 0.15 mm. Further, in order to bond a thin sheet with connection elements with no positional deviation, a jig and advanced techniques are required, and strength (tension) of the sheet itself has to be considered.
Also, in the method disclosed in the Japanese Patent No. 4102196, the connection elements are inserted one by one in the holes made in fabric subjected to the reinforcing and insulating treatments to cause high costs. In addition, there arise a problem of causing a position of deviation upon insertion of the connection elements by the influence of the thickness and rigidity of the fibers of the fabric and a problem of unstable posture (contact point upon being brought into contact with the terminal of the electronic device) of the connection elements. Further, since hole-making by a laser causes transformation (smear) in the periphery of the hole due to the processing heat, like the hole-making using a die, it is difficult to respond to a narrow pitch with the small remaining portion width.